With the development of society and the improvement of people's living standard at present, people are constantly pursuing the spiritual life while enjoying material life. Keeping pet dogs gradually becomes a popular fashion, and walking dogs also becomes the daily work of many people. Dog chain is an indispensable tool for walking a dog. The structure of an existing dog chain generally includes a chain, one end of the chain is connected with a handle through a connecting piece, and the other end of the chain is connected with a dog collar connecting buckle through a dog collar connecting piece. The dog collar connecting buckle is buckled on the dog collar, and the dog collar is worn around the neck of the dog. However, when the number of dogs is more than one, multiple dog chains of such structure are required accordingly, the dog chains are likely to wind up while walking the dogs, thus the dog chains may hurt dogs easily.